The aim of this study was to use the Optical Coherence Tomography (OCT) technique working in spectral domain
(Swept Source OCT at 1325 nm, Thorlabs, New Jersey, USA) to monitor the tissue repair in patients undergoing
periodontal plastic surgery. The evaluations were done over a period of 60 days. It was observed that 15 days after
periodontal surgery the gum was still in different healing process as compared to the observation after 60 days. Thus it is
clear that, despite some technical limitations, the OCT is an efficient method in the evaluation of regeneration gingival.
Lumineers are veneer laminates used as an alternative for aesthetic dental solutions of the highest quality, but the only
current means of its performance assessment is visual inspection. The objective of this study was to use the Optical
Coherence Tomography (OCT) technique working in spectral domain to analyze in vivo in a single patient, 14 lumineers
180 days after cementation. It was possible to observe images in various kinds of changes in the cementing line and the
laminate. It was concluded that the OCT is an effective and promising method to clinical evaluation of the cementing
line in lumineers.
OCT has been used to evaluate dental materials, and is employed here to evaluate lumineers for the first time. Lumineers are used as esthetical indirect restoration, and after wearing and aging, several undesirable features such as gaps, bubbles and mismatch can appear in which would only be seen by invasive analysis. The OCT (spectral domain SD-OCT, 930nm central wavelength) was used to evaluate noninvasively the lumineer- cement-tooth interface. We analyzed 20 specimens of lumineers-teeth that were prepared in bovine teeth and randomly allocated in 4 experimental groups (n=5) with two different cementation techniques and two different types of cementing agent (RelyX U200 and RelyX Veneer, 3M ESPE, with the adhesive recommended by the manufacture). The lumineers were made of lithium disilicate and obtained using a vacuum injection technique. The analysis was performed by using 2D and 3D OCT images, obtained before and after cementing and the thermal cycling process to simulate thermal stress in a oral cavity. Initial measurements showed that the SD-OCT was able to see through the 500μm thick lumineer, as delivered by the fabricant, and internal stress was observed. Failures were found in the cementing process and also after ageing simulation by thermal cycling. The adhesive failures as bubbles, gaps and degradation of the cementation line are the natural precursors of other defects reported by several studies of clinical follow-up (detachments, fractures and cracks). Bubble dimensions ranging from 146 μm to 1427 μm were measured and the OCT was validated as an investigative and precise tool for evaluation of the lumineer-cement-tooth.
Imaging methods are widely used in diagnostic and among the diversity of modalities, optical coherence tomography (OCT) is nowadays commercially available and considered the most innovative technique used for imaging applications, in both medical and non-medical applications. In this study, we exploit the OCT technique in the oral cavity for identification and differentiation between free and attached gingiva, as well as determining the gingival phenotype, an important factor to determination of periodontal prognosis in patients. For the animal studies, five porcine jaws were analyzed using a Swept Source SS-OCT system operating at 1325nm and stereomicroscope, as gold pattern. The SSOCT at 1325nm was chosen due to the longer central wavelength, that allows to deeper penetration imaging, and the faster image acquisition, an essential factor for clinical setting. For the patient studies, a total of 30 males and female were examined using the SS-OCT at 1325nm and computer controlled periodontal probing. 2D and 3D images of tooth/gingiva interface were performed, and quantitative measurements of the gingival sulcus could be noninvasively obtained. Through the image analysis of the animals jaws, it was possible to quantify the free gingiva and the attached gingiva, the calculus deposition over teeth surface and also the subgingival calculus. For the patient’s studies, we demonstrated that the gingival phenotype could be measured without the periodontal probe introduction at the gingival sulcus, confirming that OCT can be potentially useful in clinic for direct observation and quantification of gingival phenotype in a non-invasive approach.